I have attended school and college in Taunton for the last seven years, and am in fact embarking on another final year (this one at SCAT - art foundation) in september. Personally, having a natural yearning to be in the middle of things I feel bound to tell you that Taunton is not a very exciting place. However, that is not to say that there is absolutely nothing going on.
Culturally I think it suffers from not having any long-established University institution, and no sites of tourist interest. But while it isn't a thriving urban centre, it is nonetheless a busy county town with enough shops, pubs and restaurants for its inhabitants to get by with. Large names rarely play gigs in Taunton (although, I have to mention, Elton John did recently perform in town), but it has its own theatre and octoplex cinema, and its clubs offer various DJ acts and themed nights.
As it is still in Somerset, the area is not as rural and sparsely populated as many parts of Devon and Cornwall, and, as others have mentioned, it is within easy reach of Exeter and Bristol (my preferred city), as well as Bath and Cardiff if you're feeling more adventurous. Taunton is on the M5, and is also a routine stop on the major railway line between Penzance and Paddington, which makes getting to London much easier and quicker than you'd think: trains are regular and convenient, with the fastest services taking a mere 1 hour 50 minutes to get you to the capital.
All in all I'd say that there are many places in England that are more exciting than Taunton, but it is in no way totally dead. I hope that you enjoy your time there.